2 * This file is part of the libsigrok project.
4 * Copyright (C) 2012 Petteri Aimonen <jpa@sr.mail.kapsi.fi>
6 * This program is free software: you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation, either version 3 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
20 /* The VCD input module has the following options:
22 * numprobes: Maximum number of probes to use. The probes are
23 * detected in the same order as they are listed
24 * in the $var sections of the VCD file.
26 * skip: Allows skipping until given timestamp in the file.
27 * This can speed up analyzing of long captures.
29 * Value < 0: Skip until first timestamp listed in
32 * Value = 0: Do not skip, instead generate samples
33 * beginning from timestamp 0.
35 * Value > 0: Start at the given timestamp.
37 * downsample: Divide the samplerate by the given factor.
38 * This can speed up analyzing of long captures.
40 * compress: Compress idle periods longer than this value.
41 * This can speed up analyzing of long captures.
42 * Default 0 = don't compress.
44 * Based on Verilog standard IEEE Std 1364-2001 Version C
47 * - $var with 'wire' and 'reg' types of scalar variables
48 * - $timescale definition for samplerate
49 * - multiple character variable identifiers
51 * Most important unsupported features:
52 * - vector variables (bit vectors etc.)
53 * - analog, integer and real number variables
54 * - $dumpvars initial value declaration
64 #include "libsigrok.h"
65 #include "libsigrok-internal.h"
67 /* Message logging helpers with subsystem-specific prefix string. */
68 #define LOG_PREFIX "input/vcd: "
69 #define sr_log(l, s, args...) sr_log(l, LOG_PREFIX s, ## args)
70 #define sr_spew(s, args...) sr_spew(LOG_PREFIX s, ## args)
71 #define sr_dbg(s, args...) sr_dbg(LOG_PREFIX s, ## args)
72 #define sr_info(s, args...) sr_info(LOG_PREFIX s, ## args)
73 #define sr_warn(s, args...) sr_warn(LOG_PREFIX s, ## args)
74 #define sr_err(s, args...) sr_err(LOG_PREFIX s, ## args)
76 #define DEFAULT_NUM_PROBES 8
78 /* Read until specific type of character occurs in file.
79 * Skip input if dest is NULL.
81 * 'W' read until whitespace
82 * 'N' read until non-whitespace, and ungetc() the character
85 static gboolean read_until(FILE *file, GString *dest, char mode)
88 long startpos = ftell(file);
96 sr_err("Unexpected EOF, read started at %ld.", startpos);
100 if (mode == 'W' && g_ascii_isspace(c))
103 if (mode == 'N' && !g_ascii_isspace(c))
111 prev[0] = prev[1]; prev[1] = prev[2]; prev[2] = prev[3]; prev[3] = c;
112 if (prev[0] == '$' && prev[1] == 'e' && prev[2] == 'n' && prev[3] == 'd')
115 g_string_truncate(dest, dest->len - 3);
122 g_string_append_c(dest, c);
126 /* Reads a single VCD section from input file and parses it to structure.
127 * e.g. $timescale 1ps $end => "timescale" "1ps"
129 static gboolean parse_section(FILE *file, gchar **name, gchar **contents)
132 GString *sname, *scontents;
134 /* Skip any initial white-space */
135 if (!read_until(file, NULL, 'N')) return FALSE;
137 /* Section tag should start with $. */
138 if (fgetc(file) != '$')
140 sr_err("Expected $ at beginning of section.");
144 /* Read the section tag */
145 sname = g_string_sized_new(32);
146 status = read_until(file, sname, 'W');
148 /* Skip whitespace before content */
149 status = status && read_until(file, NULL, 'N');
151 /* Read the content */
152 scontents = g_string_sized_new(128);
153 status = status && read_until(file, scontents, '$');
154 g_strchomp(scontents->str);
156 /* Release strings if status is FALSE, return them if status is TRUE */
157 *name = g_string_free(sname, !status);
158 *contents = g_string_free(scontents, !status);
179 static void free_probe(void *data)
181 struct probe *probe = data;
183 g_free(probe->identifier);
187 static void release_context(struct context *ctx)
189 g_slist_free_full(ctx->probes, free_probe);
193 /* Remove empty parts from an array returned by g_strsplit. */
194 static void remove_empty_parts(gchar **parts)
197 gchar **dest = parts;
211 /* Parse VCD header to get values for context structure.
212 * The context structure should be zeroed before calling this.
214 static gboolean parse_header(FILE *file, struct context *ctx)
217 gchar *name = NULL, *contents = NULL;
218 gboolean status = FALSE;
221 while (parse_section(file, &name, &contents))
223 sr_dbg("Section '%s', contents '%s'.", name, contents);
225 if (g_strcmp0(name, "enddefinitions") == 0)
230 else if (g_strcmp0(name, "timescale") == 0)
232 /* The standard allows for values 1, 10 or 100
233 * and units s, ms, us, ns, ps and fs. */
234 if (sr_parse_period(contents, &p, &q) == SR_OK)
236 ctx->samplerate = q / p;
239 /* Does not happen unless time value is non-standard */
240 sr_warn("Inexact rounding of samplerate, %" PRIu64 " / %" PRIu64 " to %" PRIu64 " Hz.",
241 q, p, ctx->samplerate);
244 sr_dbg("Samplerate: %" PRIu64, ctx->samplerate);
248 sr_err("Parsing timescale failed.");
251 else if (g_strcmp0(name, "var") == 0)
253 /* Format: $var type size identifier reference $end */
254 gchar **parts = g_strsplit_set(contents, " \r\n\t", 0);
255 remove_empty_parts(parts);
257 if (g_strv_length(parts) != 4)
259 sr_warn("$var section should have 4 items");
261 else if (g_strcmp0(parts[0], "reg") != 0 && g_strcmp0(parts[0], "wire") != 0)
263 sr_info("Unsupported signal type: '%s'", parts[0]);
265 else if (strtol(parts[1], NULL, 10) != 1)
267 sr_info("Unsupported signal size: '%s'", parts[1]);
269 else if (ctx->probecount >= ctx->maxprobes)
271 sr_warn("Skipping '%s' because only %d probes requested.", parts[3], ctx->maxprobes);
275 sr_info("Probe %d is '%s' identified by '%s'.", ctx->probecount, parts[3], parts[2]);
276 probe = g_malloc(sizeof(struct probe));
277 probe->identifier = g_strdup(parts[2]);
278 probe->name = g_strdup(parts[3]);
279 ctx->probes = g_slist_append(ctx->probes, probe);
286 g_free(name); name = NULL;
287 g_free(contents); contents = NULL;
296 static int format_match(const char *filename)
299 gchar *name = NULL, *contents = NULL;
302 file = fopen(filename, "r");
306 /* If we can parse the first section correctly,
307 * then it is assumed to be a VCD file.
309 status = parse_section(file, &name, &contents);
310 status = status && (*name != '\0');
319 static int init(struct sr_input *in, const char *filename)
321 struct sr_probe *probe;
323 char name[SR_MAX_PROBENAME_LEN + 1];
329 if (!(ctx = g_try_malloc0(sizeof(*ctx)))) {
330 sr_err("Input format context malloc failed.");
331 return SR_ERR_MALLOC;
334 num_probes = DEFAULT_NUM_PROBES;
340 param = g_hash_table_lookup(in->param, "numprobes");
342 num_probes = strtoul(param, NULL, 10);
345 release_context(ctx);
350 param = g_hash_table_lookup(in->param, "downsample");
352 ctx->downsample = strtoul(param, NULL, 10);
353 if (ctx->downsample < 1)
359 param = g_hash_table_lookup(in->param, "compress");
361 ctx->compress = strtoul(param, NULL, 10);
364 param = g_hash_table_lookup(in->param, "skip");
366 ctx->skip = strtoul(param, NULL, 10) / ctx->downsample;
370 /* Maximum number of probes to parse from the VCD */
371 ctx->maxprobes = num_probes;
373 /* Create a virtual device. */
374 in->sdi = sr_dev_inst_new(0, SR_ST_ACTIVE, NULL, NULL, NULL);
377 for (i = 0; i < num_probes; i++) {
378 snprintf(name, SR_MAX_PROBENAME_LEN, "%d", i);
380 if (!(probe = sr_probe_new(i, SR_PROBE_LOGIC, TRUE, name)))
382 release_context(ctx);
386 in->sdi->probes = g_slist_append(in->sdi->probes, probe);
392 #define CHUNKSIZE 1024
394 /* Send N samples of the given value. */
395 static void send_samples(const struct sr_dev_inst *sdi, uint64_t sample, uint64_t count)
397 struct sr_datafeed_packet packet;
398 struct sr_datafeed_logic logic;
399 uint64_t buffer[CHUNKSIZE];
401 unsigned chunksize = CHUNKSIZE;
403 if (count < chunksize)
406 for (i = 0; i < chunksize; i++)
411 packet.type = SR_DF_LOGIC;
412 packet.payload = &logic;
413 logic.unitsize = sizeof(uint64_t);
418 if (count < chunksize)
421 logic.length = sizeof(uint64_t) * chunksize;
423 sr_session_send(sdi, &packet);
428 /* Parse the data section of VCD */
429 static void parse_contents(FILE *file, const struct sr_dev_inst *sdi, struct context *ctx)
431 GString *token = g_string_sized_new(32);
433 uint64_t prev_timestamp = 0;
434 uint64_t prev_values = 0;
436 /* Read one space-delimited token at a time. */
437 while (read_until(file, NULL, 'N') && read_until(file, token, 'W'))
439 if (token->str[0] == '#' && g_ascii_isdigit(token->str[1]))
441 /* Numeric value beginning with # is a new timestamp value */
443 timestamp = strtoull(token->str + 1, NULL, 10);
445 if (ctx->downsample > 1)
446 timestamp /= ctx->downsample;
448 /* Skip < 0 => skip until first timestamp.
449 * Skip = 0 => don't skip
450 * Skip > 0 => skip until timestamp >= skip.
454 ctx->skip = timestamp;
455 prev_timestamp = timestamp;
457 else if (ctx->skip > 0 && timestamp < (uint64_t)ctx->skip)
459 prev_timestamp = ctx->skip;
461 else if (timestamp == prev_timestamp)
463 /* Ignore repeated timestamps (e.g. sigrok outputs these) */
467 if (ctx->compress != 0 && timestamp - prev_timestamp > ctx->compress)
469 /* Compress long idle periods */
470 prev_timestamp = timestamp - ctx->compress;
473 sr_dbg("New timestamp: %" PRIu64, timestamp);
475 /* Generate samples from prev_timestamp up to timestamp - 1. */
476 send_samples(sdi, prev_values, timestamp - prev_timestamp);
477 prev_timestamp = timestamp;
480 else if (token->str[0] == '$' && token->len > 1)
482 /* This is probably a $dumpvars, $comment or similar.
483 * $dump* contain useful data, but other tags will be skipped until $end. */
484 if (g_strcmp0(token->str, "$dumpvars") == 0 ||
485 g_strcmp0(token->str, "$dumpon") == 0 ||
486 g_strcmp0(token->str, "$dumpoff") == 0 ||
487 g_strcmp0(token->str, "$end") == 0)
489 /* Ignore, parse contents as normally. */
493 /* Skip until $end */
494 read_until(file, NULL, '$');
497 else if (strchr("bBrR", token->str[0]) != NULL)
499 /* A vector value. Skip it and also the following identifier. */
500 read_until(file, NULL, 'N');
501 read_until(file, NULL, 'W');
503 else if (strchr("01xXzZ", token->str[0]) != NULL)
505 /* A new 1-bit sample value */
510 bit = (token->str[0] == '1');
512 g_string_erase(token, 0, 1);
515 /* There was a space between value and identifier.
518 read_until(file, NULL, 'N');
519 read_until(file, token, 'W');
522 for (i = 0, l = ctx->probes; i < ctx->probecount && l; i++, l = l->next)
526 if (g_strcmp0(token->str, probe->identifier) == 0)
528 sr_dbg("Probe %d new value %d.", i, bit);
530 /* Found our probe */
532 prev_values |= (1 << i);
534 prev_values &= ~(1 << i);
540 if (i == ctx->probecount)
542 sr_dbg("Did not find probe for identifier '%s'.", token->str);
547 sr_warn("Skipping unknown token '%s'.", token->str);
550 g_string_truncate(token, 0);
553 g_string_free(token, TRUE);
556 static int loadfile(struct sr_input *in, const char *filename)
558 struct sr_datafeed_packet packet;
559 struct sr_datafeed_meta meta;
560 struct sr_config *src;
567 if ((file = fopen(filename, "r")) == NULL)
570 if (!parse_header(file, ctx))
572 sr_err("VCD parsing failed");
577 /* Send header packet to the session bus. */
578 std_session_send_df_header(in->sdi, LOG_PREFIX);
580 /* Send metadata about the SR_DF_LOGIC packets to come. */
581 packet.type = SR_DF_META;
582 packet.payload = &meta;
583 samplerate = ctx->samplerate / ctx->downsample;
584 src = sr_config_new(SR_CONF_SAMPLERATE, g_variant_new_uint64(samplerate));
585 meta.config = g_slist_append(NULL, src);
586 sr_session_send(in->sdi, &packet);
589 /* Parse the contents of the VCD file */
590 parse_contents(file, in->sdi, ctx);
592 /* Send end packet to the session bus. */
593 packet.type = SR_DF_END;
594 sr_session_send(in->sdi, &packet);
597 release_context(ctx);
603 SR_PRIV struct sr_input_format input_vcd = {
605 .description = "Value Change Dump",
606 .format_match = format_match,
608 .loadfile = loadfile,